Apparatus for heating and ventilating



APPARATUS FOR HEATING AND VENTILATING Original Filed May 21, 1931 2Sheets-Sheet l C C. Carson July 1, 1941. v c. c. CARSON I APPARATUS FORHEATING AND VENTILATING 2 Sheets-Sheet 2 Original Filed May 21, 1931 f QQu WM NLT at. 6am

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Patented July 1, 1941 APPARATUS FOR HEATING AND 1 VENTILATINGQ 4Clifford C. CarsomtS ttLouis, Mo.

' Original application May. 21,1931, SerialLNoQ Divided and this.application March 12,1937,.SerialNo.130,575

Claims (01.257-137) This invention relates to combined heating andventilating systems for rooms or enclosures such as factory buildingsand'aims to provide an improved, efficient and economical apparatus forheating and ventilating the working area so as to insure a practicallyuniform, comfortable distribution of heated air and ventilating air,while the, upper portion of the room or enclosure is maintained at alower temperature than usual, so as to reduce the heat loss. Thisapplication is a division of my application Ser. No. 539,062, filed May21, 1931, now Patent 2,076,399.

Other aims and advantages of the invention will appear in thespecification, when considered in connection with the accompanyingdrawings, wherein:

Fig. 1 is a diagrammatic sectional view of a monitor type buildingshowing two unit heaters embodying the invention;

Fig. 2 is avertical sectional view on an enlarged scale of one of theunit heaters in Fig. 1;

Fig. 3 is a vertical sectional view of the other heater; and i .Fig.4.is a sectional view takenon the line 4-4 of Fig. 3.

Heretofore, considerable difficulty has been experienced in obtainingthe proper distribution of heating and Ventilating air in large rooms orbuildings. Ordinary unit heaters and ventilators, now in general use, donot distribute the air properly. One of the reasons is due-.to'the factthat. heated air projected into a room tends torise because itsdensity'is less than that of the" relatively cold room air through whichit passes. Further, when-the warm air in a room or building comes incontact with the relatively cold walls or surfaces, it is'cooled and itsvolume is decreased due to the lower density. As aresult,.,the;constantly.cooled or chilled air which comes in contactwith the building surfaces exposed to the outside elements produces atendency to maintain a zone of low pressure-compared with the mean roompressure in the regions adjacent to such exposed surfaces.

In most industrial or factory buildings, it is frequently necessary touse materials which permit the concentration of loss of heat totheoutside air-near those portions of the room or building composing theupper glass sash, walls, the roof, monitor sash, etc. Large areas ofglass in the roof monitors of such buildings, and the great height ofthis roof from the floor, concentrate a great proportion of thetotalheat losses in the building to these surfaces The natural tendencyof'warm air is to rise and this tendency is often increased, verymaterially by the low pressure zones against such upper surfaces of aroom due to the chilling of the room air lying against the uppersurfaces. The chilling oi the-air, in effect, produces a pull of roomair toward the exposed surfaces.

In practice, the air in a room being heated and/or ventilated by unitheaters or unit ventilators, tends to stratify the warm airconcentrating under the upper surfaces of the room. Hence, greatdirficulty is experienced in producing a condition of comfort both as totemperature and as to fresh air in that portion ofthe room near thefloor, which, in most cases, is the only space in the room which isinhabited. It is apparent that the building up of high temperaturesunder the exposed upper surfaces of the room or building, increases theloss of heat through such surfaces and increases the tendency todecreasing room pressure adjacent to such surfaces. It is the mainpurpose of this invention to heat and ventilate a room by the use ofunit heater ventilators .of improved design, which, in their operation,preventan accumulation or stratificationof high temperature air in'theupper portions of ,a room, as is obtained by the presentmethods. Theinvention also proposes to utilize improved means for projecting alarger proportion of fresh air into the space near the floor level thanis obtained by the apparatus now used. It is also a further aim toobtain a more even distribution of the heated and ventilating air andmore comfortable working conditions in all inhabited parts of a room.

In accordance with this invention,'I propose to utilize a portion offresh, outside air which is introduced for the, purpose of ventilationin producing a stream or streams of moving air at a temperature belowthe mean room temperature above a projected stream of warm air from aheating unit. The idea is to partially isolate the upper space of theroom from those spaces near. the floor and decrease the tendency of thewarm stream to rise and stratify in the upper spaces of the room. .Theidea is to partially offset the tendency of the heated air to producereduced. pressures adjacent to the exposed building surfaces whichcausean increase in the lwkage or infiltration of outside air through.cracks and openings in that portion of the building. .,;Ref;erringparticularly :to .the accompanying drawings, there isshownanyinstallation applied to an ordinarymonitor. type building [0 outlinedin Fig.,1.- In thisinstance, twoiheater-ventilator units are shown asbeing arranged at opposite sides of the building. One of them is of thefloor type which is somewhat similar to that shown in my copendingapplication, Ser. No. 398,443, filed October 9, 1929, while the other isof the suspension type somewhat similar to that shown in my copendingapplication, Ser. No. 409,657 filed November 25, 1929., now Patent No.1,820,719. The unit shown at the right hand side of" Fig. 1 and in Figs.3 and 4 comprises a casing II in which is arranged heat transferelements I2 and a series of centrifugal fans l3 of conventional designenclosed: by scrolls: [L

to be heated. The fans are conveniently arranged on a common shaft andare drivenby amotorla suitably supported on the casing Between: the

fans and the heater elements there is shown a plurality of dampers orvalves I6 for regulating the flow of air through or around the heatingelements-,-so-as to control the volume or heated air according to theroom requirements.

this i-nstance,-there is shown a by-pass l1 behind the heater elementsand separated there'- frombymeans- 0f a partition Ht. The airis admittedto the housing throughan intake opening 1-8 'near the base and an intakeconduit 2|] leading through the wallet the-building to the outside, themouth of the'intake conduit having a series-of weather louvres 2-! toprevent rainfrom beating in; In the intake conduit 28 there ispreferablyarranged a pre-heater in the formof heating elements 22' nearthe top of the conduit a-nd a by-pass 23 through which: a portion of theair maybe admitted without passing through the preheaten The by-pass 23is preferably controlled-by-a damper 24 which may be eithermanually-or--automatica-lly controlled in accordance with thetemperature. The air is first mixed in the chamber around the fanscrolls and, then; ad-

mitte'd -to the fans to be dischargedthroug-h the passagesi-n thecasinginto a mi-Xingchamber 25 above" the-heater elements l2. Fromthemixing chamber, the air is adapted to be discharged througnlarg'ehcrizontalnozzles 26 into the room or space to be heated. I 7

-; r A confining curtain' oirelatively cold, freshair is -dischargedabcveeachhot ai-rstream through ductsil'and nozzles 281 Theseaircurt-ains are preferably created by each of the centrifugal .fan's- I3, being discharged tangentially intothe ductsuz'l firom the scrolls I4.The'arrangement is. such. that the relatively cold curtains or ourtainscounteract the tendency of the hotair to rise. beforeit hasg-iven up asubstantial portion of .itssheat.v The. velocities of the two streams orstrata. are so. regulated that the mean direction of.- .traveiofthecurrents is represented bythe dotted. line,.F-'ig. 1. Thus, theheatedair may be confined. to travel across. the building before it circulatesabove the breathing line.

To control or. regulate the admission of air to the unit. and alsotoenable it to be used either as a. Ventilator .or; a heater torecirculate room air, there is shown. a damper 29 in the opening orduct; land: a. damper 30in the intakeconduit 2o. he: proportion of.fresh, outdoor air and recirculatingeroomz air can be varied at will.Moreover; either inlet can beclosed entirely while the other isopen: toconvert the unit into a re- LGircula-ting: heater, or a fresh. airheater and vena. r. .Furthen bycclosing the damper 29: and .8 1 cighedamners 16,..the unitican be used to ietsq uce ventilating air ineomthrou filial: Hz-w thout heating ny pa -crit- The suspended heater ll shown in Figs. 1 and 2 is similar in most respects to the floor typeof heater just described. In this instance, the casing is horizontal andthe cold air intake duct 20 is connected to its rear end, extendingthrough the wall of the building above the windows. The intake duct IQfor they room. air extends downwardly to a point near thefloor level.Furthermore, the outlet nozzles are curved to direct the air downwardlyat an angle of thirty degrees or more to the horizontal into the spaceto be heated. The partition l8 within the heater casing extendsforwardly to provide a separate conduit II for the by-passed air withinthe heater casing.

Thus, three separate superposed streams or strata are discharged; andthe intermediate, relatively cold air. stream travels at a lowervelocity than the upper curtain or confining stream. The hot .up. at.thermouth. The middle stratum o1'r 1-.e1a-

.tively cold. all: not; only acts: as. a confining curhairr tendingto.overcome the buoyanc of the h t: a r; butalsm separates the. hot airfrom the upper cold: air curtain. until the air is. dissipated andbeginsto liiix,v

example; the velocities and. temperaturcs; of the difilcrent: strata. ofair areso controlled; prgrcglllated that the mean direction of travel;bsllbfita niially along the dotted line in Fi 1. In. both dia rams thedotted lines. represent hc deal direction of intermingled air and.thiscircul tieninsmes a maidmum. heat distribu.- ion; the. lower.portion of the. space tobe heated and ventilated thereby greatlyreducing the temperature and heat. losses. in the upper part of hespace...

While both types of unitheaters are, shown in ab iljdi ait Willbeunderstood that a single. unit y h used very efiectivelyinrelativelysmall buildings or spaces. When two or morev units are used itis sometimes desirable to. arrange them. in staggered or offset:relation on opposite sides of the room or space.

Qbviousl the. invention is. not restricted: to the particular;embodiments. thereof herein shown and; describ cl...

- is claimcdsis:

l- .Aicombined; unit heater and ventilator-compri ng. combination, acasing; a fan within thccasine; a heat exchange element. in. the caseings. an air. intake :duct. leading Outside. of: the enclosure to. be;heated and ventilated; a heat transfer-element in. saidduct; a secondair intake chant ng: adantedito admit room air to the casing; a.dischargeduct for the heatedtair; a wide nozzle above said, discharge.duct; a conduit. leading fimmthe, f to the nozzle so. arrangedas todischar e cold air: at a high velocity above the heated aim: and a.damper-controlled bypass in saidcasing; around said heat transferelement connected. to. direct a; wide.- stream of by-passed air betweenthe relatively heated air stream and hc. air stream 'issuingfrom saidnozzle.

w -2;-, Ann-it heatenventilator comprising, incommd liqnwa casing; afanwithin the casing; a 9 19111 clt'aldmittingair into the casing; a heattransfer element: in; a portion of the casing; a discharge. outletleading from the heat transfer element; a. bypass channel aroundsaidheat transfer element arranged to discharge air above theheated'airstream: to regulate the to the fan and having a discharge nozzle abovesaid by-passed air stream arranged to project a confining stream ofrelatively cold air above the discharging lower streams.

3. A unit heater-ventilator comprising, in combination, a casing; a fanwithin the casing; a conduit for introducing fresh air into the casing;an air preheater in said conduit; a conduit for admitting room air intothe casing; an air mixing chamber adjacent to the fan; a heat transferelement in a portion of the casing; a discharge outlet leading from theheat transfer element; a by-pass channel around said heat transferelement having a discharge outlet above the heated air outlet; means toregulate the how of air through the passages; and a separate channelconnected to the fan and having a discharge nozzle above both of saidoutlets arranged to project a confining stream of cold air above thedischarging lower streams.

4. A unit heater of the class described comprising, in combination, acasing; a heat exchanger in a portion of the casing; an outlet leadingfrom the casing to discharge heated air into the space to be heated; a.by-pass within the casing around the heat exchanger connected to delivera separated stream of relatively cold air above the hot air stream;means to deliver air through the casing; means to vary the relativevolumes of air passing through the heat exchanger and said by-pass tocontrol the temperature of the heated air; and a separate air conduitconnected to said air delivering means having an outlet above andadjacent to the discharging stream of by-passed air and arranged todeliver a confining stream of cold air substantially parallel with theair streams discharging from the casing.

5. A unit heater of the class described comprising, in combination, acasing; a heat exchanger in a portion of the casing; a by-pass withinthe casing to deliver air around the exchanger; means for directing theresulting streams in separate strata into the space to be heated abovethe breathing line; dampers connected to control the volume of airpassing through the heat exchanger and by-pass; and a separate conduitconnected to said air delivering means to discharge a cold air curtainparallel with the air discharged from. said casing.

CLIFFORD C. CARSON.

